RESUMEN

The effects of noise pollution on human quality of life and health were recognised by the World Health Organisation a long time ago. There is a crucial dilemma for the study of urban noise when one is looking for proven methodologies that can allow, on the one hand, an increase in the quality of predictions, and on the other hand, saving resources in the spatial and temporal sampling. The temporal structure of urban noise is studied in this work from a different point of view. This methodology, based on Fourier analysis, is applied to several measurements of urban noise, mainly from road traffic and one-week long, carried out in two cities located on different continents and with different sociological life styles (Cáceres, Spain and Talca, Chile). Its capacity to predict annual noise levels from weekly measurements is studied. The relation between this methodology and the categorisation method is also analysed.

RESUMEN

Road traffic noise causes many health problems and the deterioration of the quality of urban life; thus, adequate spatial noise and temporal assessment methods are required. Different methods have been proposed for the spatial evaluation of noise in cities, including the categorization method. Until now, this method has only been applied for the study of spatial variability with measurements taken over a week. In this work, continuous measurements of 1 year carried out in 21 different locations in Madrid (Spain), which has more than three million inhabitants, were analyzed. The annual average sound levels and the temporal variability were studied in the proposed categories. The results show that the three proposed categories highlight the spatial noise stratification of the studied city in each period of the day (day, evening, and night) and in the overall indicators (L(And), L(Aden), and L(A24)). Also, significant differences between the diurnal and nocturnal sound levels show functional stratification in these categories. Therefore, this functional stratification offers advantages from both spatial and temporal perspectives by reducing the sampling points and the measurement time.

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RESUMEN

Currently, the need for mobility can cause significant pollution levels in cities, with important effects on health and quality of life. Any approach to the study of urban pollution and its effects requires an analysis of spatial distribution and temporal variability. It is a crucial dilemma to obtain proven methodologies that allow an increase in the quality of the prediction and the saving of resources in the spatial and temporal sampling. This work proposes a new analytical methodology in the study of temporal structure. As a result, a model for estimating annual levels of urban traffic noise was proposed. The average errors are less than one decibel in all acoustics indicators. A new working methodology of urban noise has begun. Additionally, a general application can be found for the study of the impacts of pollution associated with traffic, with implications for urban design and possibly in economic and sociological aspects.

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RESUMEN

In this paper, the stabilisation times for all 24 h of the day are analysed for 12 measurement stations located in the Spanish town of Malaga and throughout 5 years (2007-2011) of sampling environmental noise levels. For the results to be generalised to sound level measurements made in other streets or cities where there have been no long-term measurements, this study was developed for different road types and urban shapes. This distinction was made according to the types of roads indicated in other studies in which a statistically significant relationship was found between noise levels and the road type. The final objective of the study is to determine the capacity to estimate and approximate the real equivalent hourly noise level (L Aeq,1h) from the integration of a number of consecutive minutes (short-term measurements) less than 60 (L Aeq,1h ≈ L Aeq,T being T ≤ 60 min). Clearly, this strategy would save time and resources by making measurements of reduced duration. In summary and according to this analysis, a short-time measurement of 15 min is adequate to work with 90% confidence levels and errors of ±2 dB, with 80% confidence levels and errors of ±1 dB, and 50% confidence levels and errors of ±0.5 dB. However, it is necessary to consider the measurement hour period to achieve these levels of confidence due to the high variability throughout the day.

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